Uh, sorry, but I made one already for an AH map; I just never converted it to a basemap, and missed out a few states.
I also used the slightly better/more detailed maps here (
https://terrasindigenas.org.br/ - translate it into English and scroll down a little for a zoomable Google Earth overlay). I used another massive PDF that I downloaded from some Brazilian government website or other, but the PDF's too large to load on this site, and I can't for the life of me remember on where I found it. I used both as both a base for indigenous reservations and to revamp the lakes/rivers/areas of standing water. (also a little off on your base)
As I say, I was just too lazy to finish it and then remove the AH bits of the map below (tweaked state borders ect);
I also decided quite early on that most of the rivers on the existing QBAM were completely off, so I just drew them freehand and lined them up manually. I also didn't show the really small reservations.
Hope this helps, and if you do use stuff from this, please credit me.